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Greenhouse Essentials

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Want to extend your gardening season? Here’s what you need to know to take it indoors

Photos by Nicole Lapierre Photography

It makes sense that with the explosion in home gardening in 2020 due to COVID-19, many people would segue from having an outdoor garden in summer to also having a greenhouse. 

Greenhouses come in all shapes and sizes, from deck-sized covered portable units to elegant built-on greenhouses, with myriad choices in between. Before you rush out to buy, East Coast gardening enthusiasts offer some tips and tricks.

“I can’t imagine trying to garden without a greenhouse now,” says Janet Wallace, who lives on the Bay of Fundy in Albert County, N.B. “We get a lot of wind and not a lot of heat,” so her 9.2-square-metre greenhouse is ideal for raising melons, peppers, eggplants, and tomatoes. Janet and her partner use their home-built greenhouse (which cost about $700 for supplies) about nine months per year. They’re working to winterize it. They built it using recycled windows and patio doors, with a clear corrugated plastic roof. 

When her professional photography business all-but-evaporated in the spring of 2020, Nicole LaPierre had an inspiration: to start an online shop selling her prints and other things that she enjoys, including linens, sourdough starter (yes, really), and interesting houseplants. She and her husband Ted realized fairly quickly they would need more room for the plants, so they invested about $2,000 and built one in their Hammonds Plains, N.S. backyard. 

Their 18.6-square-metre south-facing greenhouse features windows that open for ventilation, a gravel floor for the handmade plant benches to stand on, and a centre aisle of repurposed cement patio stones, where a fifth bench on castors sits for more working room. They have been overwintering some plants in the greenhouse. Come spring, they’ll start transplants for their gardens and also to offer for sale. 

With cement patio tiles down the centre of the greenhouse, it’s easy to wheel around an extra greenhouse bench, and set up a table for a little relaxation time.

Having a handy spouse or friend is a great way to keep costs down when building a greenhouse. Ardent food gardener and author Elizabeth Peirce had run out of space in her home to start transplants, with seedlings on every south-facing window in her Halifax home. Her engineer husband designed a greenhouse to add on to a newly-constructed garage. With a mind to upcycling and deferring items from the landfill, they repurposed windows and a sliding glass patio door from renovations that family members had done into the design. 

“The wall the greenhouse shares with the garage is concrete slab, south-facing, which absorbs the heat of the sun and releases it slowly, reducing the need for extra heating,” Peirce says. “Our intention is for it to be mostly a solar greenhouse. There is also a poured concrete floor with electric cable running through it which is hooked up to the thermostat in the garage. You can heat it electrically during cold snaps.” She starts onions and leeks in winter in the greenhouse, followed by a succession of other food crops, and also dries herbs and seeds. 

Having a greenhouse means getting a start on seeding plants in spring, like this ‘Phenomenal’ variety of lavender.

You can’t merely put plants in the greenhouse and go away for a couple of weeks. You need to be able to water your growing darlings, often daily in warm weather. Look at options for table-top irrigation, or have a good hose and sprinkler or watering wand for keeping plants hydrated. You also need to be able to cool the greenhouse down with fans and cross ventilation (windows that open) so that heat buildup isn’t excessive.

If you’re not ready to spend a lot, go for an inexpensive but effective option to test the waters. There are numerous portable options available at gardening supply stores, or online. These range from a simple zippered shelf to walk-in portable structures, grow tunnels, and more elaborate options. 

“If you can’t do a greenhouse at first, start off with row covers and cold frames,” Wallace says. “Once you realize how much more you can grow with just a little bit more protection, there’s no going back.”

East Coast Living